As recent aging of farmers and the like, under the circumstance that labor-saving farm work is needed, a sustained-release formulation which releases a pesticidal active ingredient gradually has attracted attention. The sustained-release formulation had developed as the purpose of reducing injury to crops and improving a residual effect, and as such sustained-release formulation, for example, a coated pesticidal granule which a pesticidal granule containing a pesticidal active ingredient was coated with a resin film were known (for example, refer to JPH11-5704-A), but as such coated pesticidal granule, there is still room for improvement in views of manufacturing costs and environmental aspects, because it needed a coating process, and was worried about the resin film remains for a long-term.
As for the sustained-release pesticidal solid formulation except for above-mentioned coated pesticidal formulation, a solid pesticidal formulation comprising a pesticidal active ingredient and a porous carrier having adsorption ability was known, but depending on the pesticidal active ingredient and the porous carrier to be used, the adsorption ability and retainability of the porous carrier to the pesticidal active ingredient was not sufficient. So, it was disclosed that it could be obtained desired sustained-release by further comprising a hydrophobic material such as a wax (for example, refer to JP2011-140452-A). As described above, conventional solid pesticidal formulation comprising a pesticidal active ingredient and a porous carrier having adsorption ability could not avoid using other materials to obtain desired sustained-release.
An object of the present invention is to provide a novel sustained-release type solid pesticidal formulation without coating with a resin film or blending a hydrophobic material such as a wax.